Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Longhole open stoping
- Room-and-pillar
- Paste backfill
|
Processing |
- Centrifugal concentrator
- Smelting
- Carbon re-activation kiln
- Gravity separation
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Carbon adsorption-desorption-recovery (ADR)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 11 years (as of Jan 1, 2021) |
Latest News | Gold Fields partners with Mobilaris at Granny Smith February 24, 2021 |
Source:
p. 373, 440
The Granny Smith Gold Mine (GSM) is owned by GSM Mining Company Pty Ltd a wholly owned subsidiary of Gold Fields Ltd.
Deposit Type
- Vein / narrow vein
- Hydrothermal
Summary:
The Granny Smith region is dominated by the Mount Margaret Dome in the north-west and the Kirgella Dome in the south-east. These domes are flanked to the east and west by north-west to north striking shear zones with the central zone between the two domes dominated by north to north-north-east striking sigmoidal shear zones. These distinctly different strikes developed early in the tectonic evolution and resulted in favourable architecture for late-stage orogenic gold mineralisation at Wallaby and Granny Smith.
Orogenic greenstone gold deposits are hosted in different styles of lodes. The lodes comprise vein stock works localised by a northerly trending shear at the margin of a granodiorite. The Wallaby lodes are flat-lying alteration zones hosted in magnetite amphibole altered conglomerates. Mineralised zones show moderate to long-range geological continuity and short-range grade continuity.
Mining Methods
- Longhole open stoping
- Room-and-pillar
- Paste backfill
Summary:
Wallaby underground is accessed via a decline, and mining methods include room and pillar, bulk stopes and long-hole open stoping. The Zone 135 bulk stopes reflect the deepest mining in the LoM plan at Wallaby at ~1,450m below surface. Ground support, pillars and paste fill are designed to manage seismic activity. Operations utilise owner mining. Road haulage carts ore to the processing plant from the decline portal.
The mine has one ore stockpile in the LoM plan.
Mining of a second haulage decline from surface down to Zone 90 was completed in 2021 to improve haulage efficiency.
Wallaby underground mine is accessed via a single truck haulage decline from a portal in the Wallaby open pit. Ramp gradient is 1:7, decline and truck access profile are 5.2m wide x 5.7m high and ore drive profile is 4.6m wide x 4.6m high.
Granny Smith operates a single TSF that comprises three compartments, known as cells 1, 2 and 3. A fourth cell will be constructed in 2021 next to cell 3 to provide additional tailings capacity for the rest of the LoM. The mine also has one ore stockpile in the LoM plan.
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
.......................
|
|
|
1
|
SAG mill
|
|
|
3.4 MW
|
1
|
Ball mill
|
|
|
3.8 MW
|
1
|
Summary:
• Primary Jaw and Secondary crushing circuit
• 3.4 MW SAG Mill
• 3.8 MW Ball Mill
Processing
- Centrifugal concentrator
- Smelting
- Carbon re-activation kiln
- Gravity separation
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Carbon adsorption-desorption-recovery (ADR)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Source:
Summary:
The Granny Smith Gold mine Processing Plant was originally designed and commissioned to treat oxide gold ores mined from the Goanna, Granny and Windich pits. The plant has been periodically upgraded, based upon production requirements and ore types. The processing plant currently implements a campaign milling schedule, processing the sulphide ore mined from the Wallaby underground deposit.
The plant consists of a two-stage fresh ore crushing circuit with closed circuit screening, a standard SAG and Ball mill (SABC) grinding circuit, a gravity recovery circuit, a mechanically agitated Leach/Carbon in Pulp (CIP) circuit, a pressure Zadra elution circuit, a tailings gravity recovery circuit with regrind, a doré gold production facility, a carbon reactivation circuit, and
a thickened tailings storage facility (TSF).
Granny Smith operates a single TSF complex that comprises three compartments, known as cells 1, 2 and 3. A fourth cell (cell 4) will be constructed i ........

Recoveries & Grades:
Commodity | Parameter | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | 93.2 | 93.3 | 93.3 | 92.7 |
Gold
|
Head Grade, g/t
| ......  | ......  | ......  | 5.26 | 5.54 | 6.62 | 6.97 |
Production:
Commodity | Units | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Gold
|
koz
| ...... ^ | ......  | ......  | ......  | 280 | 290 | 284 |
All production numbers are expressed as metal in doré.
^ Guidance / Forecast.
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Operational Metrics:
Metrics | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Total tonnes mined
| ......  | ......  | 2,342 kt | 2,322 kt | 2,227 kt | 2,042 kt |
Ore tonnes mined
| ......  | ......  | 1,712 kt | 1,755 kt | 1,699 kt | 1,518 kt |
Waste
| ......  | ......  | 631 kt | 567 kt | 528 kt | 523 kt |
Tonnes processed
| ......  | ......  | 1,753 kt | 1,778 kt | 1,726 kt | 1,446 kt |
Annual processing capacity
| ......  | ......  | 3.5 Mt | 3.5 Mt | 3.5 Mt | |
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Reserves at December 31, 2021:
Mineral Resources cut-off for open pit 0.66 g/t;
Mineral Resources cut-off for underground 2.1 – 3.0 g/t;
Mineral Reserves cut-off for underground 2.6 – 3.5 g/t.
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
Stockpiles
|
26 kt
|
Gold
|
5.55 g/t
|
5 koz
|
Proven
|
In-Situ (UG)
|
2,212 kt
|
Gold
|
4.93 g/t
|
351 koz
|
Proven
|
Total
|
2,239 kt
|
Gold
|
4.94 g/t
|
355 koz
|
Probable
|
In-Situ (UG)
|
10,363 kt
|
Gold
|
5.58 g/t
|
1,861 koz
|
Proven & Probable
|
Stockpiles
|
26 kt
|
Gold
|
5.55 g/t
|
5 koz
|
Proven & Probable
|
In-Situ (UG)
|
12,575 kt
|
Gold
|
5.47 g/t
|
2,211 koz
|
Proven & Probable
|
Total
|
12,601 kt
|
Gold
|
5.47 g/t
|
2,216 koz
|
Measured
|
Stockpiles
|
26 kt
|
Gold
|
5.55 g/t
|
5 koz
|
Measured
|
In-Situ (UG)
|
5,472 kt
|
Gold
|
6.03 g/t
|
1,061 koz
|
Measured
|
Total
|
5,498 kt
|
Gold
|
6.03 g/t
|
1,066 koz
|
Indicated
|
In-Situ (UG)
|
27,934 kt
|
Gold
|
5.88 g/t
|
5,279 koz
|
Inferred
|
In-Situ (OP)
|
357 kt
|
Gold
|
1.88 g/t
|
22 koz
|
Inferred
|
In-Situ (UG)
|
10,663 kt
|
Gold
|
5.06 g/t
|
1,735 koz
|
Inferred
|
Total
|
11,020 kt
|
Gold
|
4.96 g/t
|
1,757 koz
|
Total Resource
|
Stockpiles
|
26 kt
|
Gold
|
5.55 g/t
|
5 koz
|
Total Resource
|
In-Situ (OP)
|
357 kt
|
Gold
|
1.88 g/t
|
22 koz
|
Total Resource
|
In-Situ (UG)
|
44,069 kt
|
Gold
|
5.7 g/t
|
8,076 koz
|
Total Resource
|
Total
|
44,452 kt
|
Gold
|
5.67 g/t
|
8,102 koz
|
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